Accuracy of Preoperative Ultrasonography for Cubital Tunnel Syndrome: A Comparison with Intraoperative Findings

Morphological Changes of Medial Epicondyle-Olecranon Ligament and Ulnar Nerve in the Cubital Tunnel Syndrome: An Ultrasonic Study

Objective

Few studies have performed detailed ultrasound measurements of medial epicondyle‐olecranon (MEO) ligament that cause the entrapment of ulnar nerve. This study aims to comprehensively evaluate dynamic ultrasonographic characteristics of MEO ligament and ulnar nerve for clinical diagnosis and accurate treatment of cubital tunnel syndrome (CuTS).

Methods

Thirty CuTS patients (CuTS group) and sixteen healthy volunteers (control group) who underwent ultrasound scanning from October 2016 to October 2020 were retrospectively collected, with 30 elbows in each group. Primary outcomes were thickness at six points, length and width of MEO ligament. Secondary outcomes were thickness of ulnar nerve under MEO ligament at seven parts and the cross‐sectional area (CSA) of ulnar nerve at proximal end of MEO ligament (P_0 mm). The thickness of MEO ligament and ulnar nerve in different points of each group was compared by one‐way ANOVA analysis with Bonferroni post hoc test, other outcomes were compared between two elbow positions or two groups using independent‐samples t test.

Results

Thickness of MEO ligament in CuTS group at epicondyle end, midpoint in transverse view, olecranon end, proximal end, midpoint in axial view, and distal end was 0.67 ± 0.31, 0.37 ± 0.18, 0.89 ± 0.35, 0.39 ± 0.21, 0.51 ± 0.38, 0.36 ± 0.25 at elbow extension, 0.68 ± 0.34, 0.38 ± 0.27, 0.77 ± 0.39, 0.32 ± 0.20, 0.48 ± 0.22, 0.32 ± 0.12 (mm) at elbow flexion, respectively. Compared with control group, they were significantly thickened except for proximal end at elbow flexion. MEO ligament thickness at epicondyle end and olecranon end was significantly larger than midpoint in two groups. No significant difference was found in length and width of MEO ligament among different comparisons. Ulnar nerve thickness at 5 mm proximal to MEO ligament (P_5 mm, 3.25 ± 0.66 mm) was significantly increased than midpoint of MEO ligament (Mid), distal end of MEO ligament (D_0 mm), 5 mm (D_5 mm), 10 mm (D_10 mm) distal to MEO ligament at extension in CuTS group. Compared with control group, ulnar nerve thickness at P_5 mm in CuTS group was significantly increased at extension position, at D_5 mm and D_10 mm was significantly decreased at flexion position. CSA of ulnar nerve at extension position (14.44 ± 4.65 mm²) was significantly larger than flexion position (11.83 ± 3.66 mm²) in CuTS group, and CuTS group was significantly larger than control group at two positions.

Conclusions

MEO ligament in CuTS patients was thickened, which compressed ulnar nerve and caused its proximal end swelling. Ultrasonic image of MEO ligament thickness was a significant indicator for CuTS and can guide surgeons in selecting the appropriate treatment.

Evaluation of acromial spur using ultrasonography

BACKGROUND

The presence of an acromial spur implies a rotator cuff disorder due to impingement between the acromial spur and the rotator cuff. The purpose of the study was to observe acromial spurs using ultrasonography and to compare measurements between plain radiographs and sonograms.

METHODS

We retrospectively enrolled 51 consecutive patients with acromial spurs, which were interpreted on preoperative plain radiographs (supraspinatus outlet view and 30° caudal tilt) and preoperative sonograms. The ultrasonography transducer was held vertically and continuously moved laterally, which corresponded to the long axis of the long head of the biceps. The distance from the most distal margin of the original acromion to the most projected point of the acromial spur was measured.

RESULTS

No significant difference was found between the plain radiograph and ultrasonography measurements (p=0.186). A moderate to strong correlation was detected between the ultrasonography and supraspinatus outlet-view measurements (r=0.776, p=0.000).

CONCLUSIONS

Anteriorly projected acromial spurs were well-visualized by ultrasonography. No discrepancy in acromial spur length was detected between the use of plain radiography (supraspinatus outlet view and 30° caudal-tilt view) and ultrasonography. The correlation coefficients between the plain radiography and ultrasonography measurements exceeded 0.7.

Distribution of Peripheral Nerve Injuries in Patients with a History of Shoulder Trauma Referred to a Tertiary Care Electrodiagnostic Laboratory

Peripheral nerve injury after shoulder trauma is an underestimated complication. The distribution of the affected nerves has been reported to be heterogeneous in previous studies. This study aimed to describe the distribution of peripheral nerve injuries in patients with a history of shoulder trauma who were referred to a tertiary care electrodiagnostic laboratory. A retrospective chart review was performed for all cases referred to a tertiary care electrodiagnostic laboratory between March 2012 and February 2020. The inclusion criteria were a history of shoulder trauma and electrodiagnostic evidence of nerve injury. Data on patient demographics, mechanism of injury, degree of weakness, clinical outcomes at the final follow-up, and electrodiagnostic results were retrieved from medical records. Fifty-six patients had peripheral nerve injuries after shoulder trauma. Overall, isolated axillary nerve injury was the most common. A brachial plexus lesion affecting the supraclavicular branches (pan-brachial plexus and upper trunk brachial plexus lesions) was the second most common injury. In cases of shoulder dislocation and proximal humerus fracture, isolated axillary nerve injury was the most common. Among acromioclavicular joint injuries and clavicular fractures, lower trunk brachial plexus injuries and ulnar neuropathy were more common than axillary nerve or upper trunk brachial plexus injuries. Patients with isolated axillary nerve lesions showed a relatively good recovery; those with pan-brachial plexus injuries showed a poor recovery. Our study demonstrated the distribution of peripheral nerve injuries remote from displaced bony structures. Mechanisms other than direct compression by displaced bony structures might be involved in nerve injuries associated with shoulder trauma. Electrodiagnostic tests are useful for determining the extent of nerve damage after shoulder trauma.

In idiopathic cubital tunnel syndrome, ulnar nerve excursion and instability can be reduced by repairing Osborne's ligament after simple decompression

Osborne's modified decompression involves repairing Osborne's ligament beneath the ulnar nerve after simple decompression for idiopathic cubital tunnel syndrome. In this retrospective interrupted time series, 31 patients underwent modified simple decompression and 20 patients underwent conventional simple decompression. In the modified simple decompression group, the ulnar nerve length was measured at operation in full elbow flexion and extension before and after repair of Osborne's ligament. Ulnar nerve instability during elbow motion was measured using ultrasonography before operation and at 12 months after operation. In patients treated by modified simple decompression, the ulnar nerve length in full elbow flexion reduced significantly after repair of Osborne's ligament. At 12 months after surgery, the grade of ulnar nerve instability was lower in the modified simple decompression group than in the conventional simple decompression group. The clinical outcomes did not differ significantly between the groups at 24 months after operation. Level of evidence: III.

Features of the Ulnar Nerve Predicting Postoperative Prognosis in Idiopathic Cubital Tunnel Syndrome: Three Distinct Features of the Ulnar Nerve

PURPOSE

This retrospective case-control study was performed to determine the relationships between features of the ulnar nerve and postoperative outcomes following in situ decompression in idiopathic cubital tunnel syndrome (CuTS).

METHODS

The study population consisted of 86 patients who had undergone surgery for CuTS. We evaluated demographic factors, hand dominance, symptom onset time, time from diagnosis to surgery, findings of electrodiagnosis (nerve conduction velocity/electromyography), and preoperative clinical status. Intraoperatively, the ulnar nerve was defined as a definitively compressed, abnormally enlarged, or inflammatory lesion. Clinical improvements were evaluated at least 2 years after surgery.

RESULTS

Fifty-four patients showed improvement after surgery in terms of the modified McGowan grade and were designated as group 1. Meanwhile, 32 patients with unchanged or aggravated status were classified as group 2. Preoperative status, as determined by the modified McGowan grade, Boston Symptom Severity Scale score, severity of electrodiagnosis, and predominant symptoms were similar between the groups (all, P > 0.05). On regression analysis, only the classification of nerve lesions and the time from diagnosis to surgery had an impact on postoperative outcome (all, P < 0.05). Especially, enlarged ulnar lesion predicted poor prognosis (P = 0.003).

CONCLUSIONS

Ulnar nerve enlargement, grossly detected intraoperatively, and long interval between diagnosis and surgery were independently associated with poor prognosis of CuTS. Among the anatomic structures involved in the generation of CuTS, the medial epicondyle showed a strong association with enlarged nerve lesions.

Open cubital and carpal tunnel release using wide-awake technique: reduction of postoperative pain

Purpose

This study aimed to compare the efficacy of and patient satisfaction with the wide-awake local anesthesia with no tourniquet (WALANT) technique in open cubital and carpal tunnel release surgery.

Methods

From January 2016 to February 2017, 20 cubital tunnel syndrome (CuTS) patients were in a wide-awake (WA) group and 22 in a general (GA) anesthesia group in . Also, 20 carpal tunnel syndrome (CTS) patients were in a WA group, 22 in a local anesthesia (LA) group, and 20 in a GA group. Injection pain, perioperative pain, and postoperative pain were assessed using a 10-point pain VAS. In CuTS, functional outcome on the “quick” Disabilities of the Arm, Shoulder, and Hand questionnaire were evaluated. In CTS, subjective outcomes were assessed using the Korean version of the Michigan Hand Outcomes Questionnaire.

Results

Both CuTS and CTS showed significant postoperative pain reduction in group WA. In CuTS, group WA had less pain than group GA up to 48 hours after surgery (P<0.05). Supplemental opioid injections were used on hospitalization day by 12% of group WA and 35% of group GA. In CTS, the postoperative VAS scores in group WA were lower during the first 24 hours than groups LA and GA (P<0.05). Opioid injections were used on hospitalization day by 5% of WA, 18% of LA, and 32% of group GA. There was no difference in postoperative functional outcomes according to anesthesia method in CuTS or CTS.

Conclusion

Cubital and carpal tunnel surgery using the WALANT technique was comparable in function to other anesthesia methods and superior for pain. Immediate postoperative pain was much lower than other groups, which could reduce the use of opioids during hospitalization.